These panels charge the cart at about 3 amps. Welding or driving draws up to 150 amps, but only in short bursts. To my surprise I have to disconnect the panel after a day or two to keep from overcharging the pack. I probably only charge one day a week. I better add an inverter so I can power my office and other tools from this thing.

Warning:This thing is so damn cool you'll smile too much and hurt your face.I probably should have put the cover back over the batteries before he started welding, cuz batteries can make hydrogen which can go pop.You're smart kids, you can figure out other safety warnings for this thing.

Step 1: The Panels

A scrap dealer gave me a great deal on some badly weathered solar panels from the coast guard. He was on his way to his house in Zihuatanejo and was overloaded. Also he wanted to do us a favor. Thank you kind sir!

To my surprise most of the panels worked okay and the seagull poop cleaned off pretty well, althought the aluminum frames were pretty corroded.
These are 20 watt panels that produce an open-circuit voltage of about 18 volts. That's about right for a 12 volt battery, which is what they were made for. We wired up three of them to charge the 36 volt golf cart battery bank. Then I wired another three the same way to double the amperage. I tried them all in series, but it didn't work nearly as well. Only about half as many amps flowed.

I probably should have put the cover back over the batteries before he started welding, cuz batteries can make hydrogen which can go pop.

Wouldn't it be safer to leave the cover off? By leaving it on, you concentrate the hydrogen in one place, and a stray spark bouncing into the box could ignite it. By leaving it open, the gas can rapidly rise away, and any breeze will disperse it.

Our electric truck has a camper shell over the bed and batteries, and when charging we always open the rear window to vent any hydrogen. We feel that we should try to catch it and install a fuel cell to extend the range.

When charging any non-sealed lead-acid battery pack, hydrogen will be vented. Ours vent more than most because we are using a very crude Lester charger, which just dumps in a bunch of electricity, then cuts the amperage as the batteries charge.

And I was joking about the fuel cell. They're useful in spacecraft, but pretty dumb in cars.

I have one of the extended bed Cushmans with the 40mph transmissions in it. it was one at a navy aquatic complex used for launching boats in the water so it is blue. the engine is out of it because I have to put in the new clutch my dad got for it and then I have to redo the brake lines because they are old, brittle, and leaked break fluid all over our garage floor without us knowing when we put it up on jack stands to unbolt the engine. it is a 2 story garage me and my dad built so we didn't notice the break fluid for a while. amazingly, a couple months later when it is totally dry, Oildry still managed to remove most of it.:)

Even though I am REAL CHEAP, just to keep down the hastle, you might google for a 'DCBattery Charge Controller' or similar. You size it about 30% larger than the BATTERIES you are using in VA and get the one (or a multi-volt one) for the number of volts coming in. ... Now whenever your buggy is in the sun, and the batteries need charging they get it without over charging. Or at least that is the concept. Great instructable, ... And I have a 2x4ft fresnel lens, neat toy, but sets fires easily :)

solar golf cart! I'm building one as we speak! I will use a charge controller though. The solar panels you are using, I've seen the same type on ebay for $$$!! Those are excellent panels for golf cart applications. The Gov't just throws stuff away!!

About This Instructable

Bio:Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of www.zcorp.com, manufacturers of "3D Printer" output devices. His detailed drawings of traditional ...read more »